1. Field of the Invention
The present invention relates, in general, to collapsible tent frames and, more particularly, to a one-touch assembling collapsible tent frame suitable for being easily and quickly assembled or disassembled, tightly stretching and sustaining the roof of a tent by a center pole, stably supporting the tent on the ground, and making pitching or striking the tent easy and quick.
2. Description of the Prior Art
As well known to those skilled in the art, a tent is a collapsible shelter of canvas or other material stretched over and sustained by a frame and is used for camping outdoors or as a temporary structure.
It is preferable for such a tent to be easily and quickly pitched or struck when necessary, so a frame for such tents is preferably designed for being collapsible. In addition, the frame for tents has to be rigid so as to allow a user to use a tent for a lengthy period of time.
Examples of typical collapsible tent frames are referred to U.S. Pat. Nos. 4,641,676 (issued on Feb. 10, 1987), 4,779,635 (issued on Oct. 25, 1988), 4,947,884 (issued on Sep. 14, 1990), 5,244,001 (issued on Sep. 14, 1993), 5,275,188 (issued on Jan. 4, 1994) and 5,421,356 (issued on Jan. 6, 1995).
As shown in FIGS. 1 and 2, the above U.S. patents individually disclose a collapsible tent frame which comprises four side poles 1. The above side poles 1 are adjustable in height and individually have a side pole connector 10 at the top end and a claw 16 at the lower end, thus being held on the ground. A side pole slider 15 is movably fitted over each of the side poles 1 at a position under the connector 10, thus being slidable along the side pole 1 in opposite directions.
The four side poles 1 are coupled to each other into a collapsible structure by a plurality of side pole ribs 2a and 2b which are coupled to each other into a scissor structure.
In such a case, the first side pole ribs 2a are coupled to each other through hinge joints 20 and are hinged to the sliders 15 at the outside ends. Meanwhile, the second side pole ribs 2b are coupled to each other through hinge joints 25 and are hinged to the connectors 10 at the outside ends.
A center pole connector 30 is fixed to the lower end of a center pole 3 and is coupled to the joints 20 of the first side pole ribs 2a through a plurality of first center pole ribs 2c. Meanwhile, a center pole slider 35 is movably fitted over the center pole 3 and is coupled to the joints 25 of the second side pole ribs 2b through a plurality of second center pole ribs 2d.
In such a case, the first and second center pole ribs 2c and 2d are coupled to each other into a scissor structure in the same manner as that described for the side pole ribs 2a and 2b.
In order to strike a tent, the four side poles 1 are moved to the center of the tent frame as shown in FIG. 2, so the center pole 3 moves down in the center pole slider 35 while folding the scissor assemblies of the pole ribs 2a, 2b, 2c and 2d and collapsing the tent frame. In such a case, the collapsed frame has a reduced volume, thus allowing a user to easily and conveniently carry the tent. On the other hand, when the four side poles 1 are pushed outwardly at the same time, the center pole 3 moves up in the center pole slider 35 so as to stretch and sustain the roof of the tent, thus pitching the tent.
However, the above collapsible tent frame has the following problems. That is, it is necessary for a user to use separate tools while assembling or disassembling the tent frame, so the tent frame is inconvenient to users. In addition, the tent frame is designed for making the side poles 1 be always vertically positioned on the ground when stretching the frame. Therefore, the tent frame may be unexpectedly collapsed on the ground.
As shown in FIG. 3, the center pole 3 has a telescopic structure, with a compression coil spring 39 being positioned inside a cylinder of the center pole 3 and biasing a tension member of the center pole 3 upwardly so as to effectively stretch and sustain the roof of the tent when pitching the tent. However, the above spring 39 may lose desired elasticity when it is used for a lengthy period of time, so the center pole 1 may fail to tightly stretch and sustain the roof of the tent and spoil the appearance of the tent when the tent is pitched. In such a case, the canvas or other material 100 of the tent may violently flutter in the wind, thus generating noises irritating those around and inside the tent and being sometimes unexpectedly removed from the frame.
FIG. 4 shows a means for selectively stopping the side pole slider 15 on the upper portion of a side pole 1 when pitching the tent. As shown in the drawing, the slider stop means of the above frame comprises a hole 12 which is formed at the upper portion of each side pole 1. A plate spring 13, integrated with a finger-operable stopper 14, is positioned inside the side pole 1 with the stopper 14 being normally and elastically projected from the hole 12.
However, the above slider stop means has the following problems. That is, it is necessary for a user to press the stopper 14 into the hole 12 with a finger tip so as to allow the slider 15 to pass over the stopper 14 while pitching or striking a tent. Therefore, the user's finger may be unexpectedly caught between the slider 15 and the side pole 1, thus being injured. In addition, when the stopper 14 is pressed into the hole 12 by a finger, the stopper 14 may be unexpectedly caught by the edge of the hole 12, thus failing to be elastically projected from the hole 12 even when the finger pressing force is removed from the stopper 14. In such a case, it is necessary for a user to insert a longitudinal member, such as a pipe, into the side pole 1 from the bottom prior to skillfully manipulating the spring 13 so as to project the stopper 14 outside the hole 12. Alternately, the user has to remove the connector 10 from the side pole 1 prior to skillfully manipulating touching the spring 13 so as to project the stopper 14 outside the hole 12. Therefore, such a slider stop means is inconvenient to users.